CONCERO 65 Monoblock Power Amplifier

“In designing the Concero directly heated Tube Monoblocks we endeavoured to produce a design that has all the sonic virtues of the best Single Ended amplifiers, but with absolutely none of their shortcomings. In other words, with no limitations AND all of the benefits sonically of true SET amplification. We strongly believe we have succeeded.”

Stavros DanosDISEÑO: ARIES CERAT

Driving the output tube, is a major task, where almost all SET amplifiers fall short and using tubes not adequate to the task. Tubes with high Rp and small current swing capabilities. What we choose to use is a small SET amplifier consisting of the special quality Siemens E280F super-tube, with it’s own power and bias supply.

This ultra wide-bandwidth and very high trans-conductance tube is transformer coupled to the grid of the output tube using a very wide-bandwidth interstage transformer. No RC coupling is used in any of our amplifiers.

The output transformer weighs more than many SET amplifier’s total weight. The highest quality massive core of the output transformer used in the design, is mandatory for delivering true undistorted higher and lower bass, and driving any speaker through complex musical content.

Many SET amplifiers exhibit distortion when driving speakers with complex music due to core saturation. Our output transformer can output well above it’s rated power at 20Hz,so at 65W intermodulation aftefacts are next to zero.

Separate power supplies are used throughout our design, using 4 toroidal transformers rated at over 1500VA total.Separate toroids are used for driver stage, output stage,filaments and bias circuits.

Driver and output is ground-choke regulated with huge energy banks for each channel.The Concero 65 are available in two chassis options, classic and the more compact 2018 facelift version.

DRIVER STAGE

814 DHT tube, amorphous C-Core,bifilar wound interstage transformer

High power film capacitor (choke regulated) banks

Triple filtered filaments

OUTPUT STAGE

Parallel 813 SET stage,ultra low noise adjustable bias circuits

High power film capacitors, choke regulated banks

The film Capacitors used,have ~1000 times the max current surge rating than any electrolytic used in other amplifiers,and 10 times less ESR/ESL than any electrolytic capacitor

Choke used is a 11kg-core inductor, providing extra energy storage

Triple filtered filaments

Oversized ,highest quality output transformer

700.000uF total primary and secondary circuits capacitance

Separate toroidal transformers for output stage,driver and filaments, 1500VA total